Solid-state battery manufacturing method

ABSTRACT

An all-solid-state battery manufacturing apparatus disclosed herein includes a transport apparatus, a press roller, and an adhesive provision apparatus. The transport apparatus transports an active material layer. The press roller has a foil attachment surface, which is a cylindrical surface to which the current collection foil is to be attached. The press roller rotates and moves the current collection foil attached to the foil attachment surface to the surface of the active material layer being transported by the transport apparatus and presses the current collection foil and the active material layer between the press roller and the transport apparatus. The adhesive provision apparatus is provided on a movement path of the current collection foil rotated and moved by the foil attachment surface of the press roller, and provides an adhesive to the current collection foil attached to the press roller.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present specification claims priority on the basis of JapanesePatent Application No. 2020-118341 filed on Jul. 9, 2020, the contentsof which are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present teaching relates to an all-solid-state battery manufacturingapparatus and an all-solid-state battery manufacturing method.

2. Description of the Related Art

Secondary batteries have widely been used as portable power sources forpersonal computers, mobile telephones, and the like, and as vehicledriving power sources for EVs (electric vehicles), HVs (hybridvehicles), PHVs (plug-in hybrid vehicles), and the like. As one exampleof a secondary battery, development of an all-solid-state battery usinga solid electrolyte instead of a liquid electrolyte has beenprogressing. In an all-solid-state battery, a first current collector, afirst active material layer, a solid electrolyte layer, a second activematerial layer, and a second current collector are stacked in the statedorder. If the relative positions of the multiple stacked layers shift,there is a possibility that the battery performance will change.Accordingly, in order to suppress shifting of the positions of themultiple layers, a technique has been proposed in which two layers thatare adjacent to each other are adhered. For example, an all-solid-statebattery disclosed in Japanese Patent Application Publication No.2017-204377 is manufactured by adhering a first current collector and afirst active material layer using a thermoplastic resin.

SUMMARY

According to the conventional all-solid-state battery manufacturingmethod, multiple layers are bonded by heating and compressing themultiple layers in a stacking direction using a flat plate in a state inwhich adhesive has been arranged between the layers to be adhered. Withthis method, it is difficult to shorten the amount of manufacturingtime. Accordingly, a method according to which multiple layers can beadhered more suitably has been desired.

Atypical object of the present teaching is to provide an all-solid-statebattery manufacturing apparatus and an all-solid-state batterymanufacturing method which enable multiple layers constituting a batteryto be adhered more appropriately.

In order to realize the object, an all-solid-state battery manufacturingapparatus according to an aspect disclosed here is a manufacturingapparatus for manufacturing an all-solid-state battery in which acurrent collection foil and an active material layer are stacked, themanufacturing apparatus including: a transport apparatus configured totransport the active material layer supported on a support surface; apress roller that has a foil attachment surface, which is a cylindricalsurface to which the current collection foil supplied from the outsideis to be attached, and that is configured to rotate and move the currentcollection foil attached to the foil attachment surface to a surface ofthe active material layer being transported by the transport apparatusby rotating using a central axis of the cylindrical surface as arotational axis, and to press the current collection foil and the activematerial layer in a thickness direction between the press roller and thesupport surface of the transport apparatus; and an adhesive provisionapparatus that is provided on a movement path of the current collectionfoil rotated and moved by the foil attachment surface of the pressroller, and that is configured to provide an adhesive to the currentcollection foil attached to the press roller.

With the all-solid-state battery manufacturing apparatus according tothe present disclosure, the current collection foil provided with theadhesive and the active material layer can be stacked and pressed(compressed) while the current collection foil is rotated and moved bythe press roller. Accordingly, it is possible to adhere the currentcollection foil and the active material layer in a shorter amount oftime compared to the case of pressing the current collection foil andthe active material layer using a flat plate or the like.

In one desirable aspect of the manufacturing apparatus disclosed herein,the adhesive provision apparatus includes an adhesive roller. Theadhesive roller includes an adhesive contact surface, which is acylinder surface that comes into contact with the adhesive. The adhesiveroller adjusts a thickness of the adhesive on the current collectionfoil attached to the foil attachment surface of the press roller byrotating using an axis parallel to the rotational axis of the pressroller as a rotational axis.

If the current collection foil and the active material layer are pressedusing the flat plate, it is possible to reduce the thickness of theadhesive between the current collection foil and the active materiallayer by extending the amount of pressing time. However, as describedabove, it is difficult to shorten the amount of manufacturing time ifthe flat plate is used. Also, if the current collection foil and theactive material layer are simply pressed using the press roller, theamount of time for which the pressing pressure is applied is shortened,and therefore there is also a possibility that the thickness of theadhesive between the current collection foil and the active materiallayer will not decrease and the shape of the stacked body of theall-solid-state battery will be disturbed. If the shape of the stackedbody is disturbed, deterioration of the battery performance and the likewill occur in some cases as well. In contrast to this, due to thethickness of the adhesive attached on the current collection foil beingadjusted (reduced) in advance by the adhesive roller, the currentcollection foil and the active material layer are adhered in a shortamount of time and the shape of the stacked body is also less likely tobe disturbed. Accordingly, the current collection foil and the activematerial layer are adhered more suitably.

In one desirable aspect of the manufacturing apparatus disclosed herein,the adhesive provision apparatus further includes a supply apparatusthat supplies adhesive to the adhesive contact surface of the adhesiveroller. The adhesive roller adjusts the thickness of the adhesive whiletransferring the adhesive supplied to the adhesive contact surface bythe supply apparatus to the current collection foil attached to the foilattachment surface. In this case, the step of providing the adhesive tothe current collection foil and the step of adjusting the thickness ofthe adhesive on the current collection foil are performed at the sametime (in parallel). Accordingly, the current collection foil and theactive material layer are adhered more efficiently. However, theadhesive may also be provided to the current collection foil using amethod other than transfer using the adhesive roller (e.g., a methodsuch as dripping, coating, or spraying).

In one desirable aspect of the manufacturing apparatus disclosed herein,the adhesive is a photocurable adhesive that is cured due to a curinglight being emitted thereto. The manufacturing apparatus furtherincludes a curing light emission unit configured to emit the curinglight to the adhesive on the current collection foil attached to thepress roller. In this case, unlike the case of using a hot melt that ismelted by being heated as the adhesive, there is no need to heat theadhesive, and therefore the manufacturing efficiency is further improvedand there is no adverse effect on the members of the all-solid-statebattery due to heat. Furthermore, even if the temperature of theall-solid-state battery rises during use, the adhesive is not melted,and therefore the shape is not likely to change either. Accordingly, thecurrent collection foil and the active material layer are adhered moresuitably. However, it is also possible to use a hot melt or the like asthe adhesive.

In a desirable aspect of the manufacturing apparatus disclosed herein,at least a portion of the adhesive roller is made of a material throughwhich the curing light passes. A curing light emission unit emits thecuring light through the adhesive roller to the adhesive on the currentcollection foil attached to the press roller. In this case, the curinglight is emitted to the adhesive while the thickness of the adhesive onthe current collection foil is adjusted by the adhesive roller.Accordingly, the degree of freedom in the arrangement of the apparatusesimprove, and the current collection foil and the active material layerare adhered more efficiently. However, it is also possible to emit thecuring light to the adhesive without allowing the curing light to passthrough the adhesive roller.

In one desirable aspect of the manufacturing apparatus disclosed herein,the press roller includes a plurality of ventilation holes that extendfrom the foil attachment surface to the interior. The press rollerattaches the current collection foil to the foil attachment surface bysuctioning a gas from the ventilation holes to the interior. In thiscase, the press roller can easily and suitably attach the currentcollection foil to the foil attachment surface.

In one desirable aspect of the manufacturing apparatus disclosed herein,a viscosity of the adhesive when provided to the current collection foilis 100 mPa•s to 5000 mPa•s. In this case, the adhesive is suitablyprovided to the current collection foil and adhesion of the currentcollection foil and the active material layer is also performedsuitably. Also, in the case where the surface of the current collectionfoil is coated with carbon, if the viscosity of the adhesive is too low,there is a possibility that the adhesive will excessively permeate thecarbon layer and the current collection foil and the active materiallayer will not be sufficiently adhered. Conversely, if the viscosity ofthe adhesive is too high, there is a possibility that the adhesive willnot be likely to permeate the carbon layer and the thickness of theadhesive will not decrease sufficiently. Accordingly, if the surface ofthe current collection foil is coated with carbon, the viscosity of theadhesive may be 500 mPa•s to 1500 mPa•s. In this case, it is possible toobtain a favorable adhesive thickness and adhesiveness.

An all-solid-state battery manufacturing method according to one aspectdisclosed herein is a manufacturing method for manufacturing anall-solid-state battery in which a current collection foil and an activematerial layer are stacked, the manufacturing method including: acurrent collection foil attachment step of attaching the currentcollection foil to a foil attachment surface of a press roller thatincludes the foil attachment surface, which is a cylindrical surface,and that is configured to rotate using a central axis of the cylindricalsurface as a rotational axis; an adhesive provision step of providing anadhesive on the current collection foil attached to the foil attachmentsurface; and a pressing step of rotating and moving the currentcollection foil attached to the foil attachment surface to a surface ofthe active material layer being transported by a transport apparatus byrotating the press roller, and pressing the current collection foil andthe active material layer in a thickness direction between the pressroller and the transport apparatus.

According to the all-solid-state battery manufacturing method accordingto the present disclosure, the current collection foil provided with theadhesive and the active material layer can be stacked and pressed(compressed) while the current collection foil is rotated and movedusing a press roller. Accordingly, it is possible to adhere the currentcollection foil and the active material layer in a shorter amount oftime compared to the case of pressing the current collection foil andthe active material layer using a flat plate or the like.

One favorable aspect of the manufacturing method disclosed hereinfurther includes a thickness adjustment step. In the thicknessadjustment step, the thickness of the adhesive is adjusted by bringingan adhesive contact surface of an adhesive roller that has the adhesivecontact surface, which is a cylinder surface, and that is configured torotate using an axis parallel to the rotational axis of the press rolleras the rotational axis into contact with the adhesive on the currentcollection foil attached to the foil attachment surface. In this case,as described above, the thickness of the adhesive attached on thecurrent collection foil is adjusted in advance using the adhesiveroller, and thereby the current collection foil and the active materiallayer are adhered in a short amount of time, and the shape of thestacked body is less likely to be disturbed.

In one suitable aspect of the manufacturing method disclosed herein, theadhesive provision step and the thickness adjustment step are performedat the same time by transferring the adhesive supplied to the adhesivecontact surface of the adhesive roller to the current collection foilattached to the foil attachment surface. In this case, the currentcollection foil and the active material layer are adhered moreefficiently.

In one desirable aspect of the manufacturing method disclosed herein,the adhesive is a photocurable adhesive that is cured due to a curinglight being emitted thereto, and a photocurable adhesive that is cureddue to a curing light such as ultraviolet rays and/or visible light raysbeing emitted thereto is desirable. The manufacturing method furtherincludes a curing light emission step of emitting the curing light tothe adhesive. In this case, there is no need to heat the adhesive, andtherefore the manufacturing efficiency further improves, and there is noadverse effect on the material of the all-solid-state battery due toheat. Furthermore, the shape is less likely to change due to heating ofthe all-solid-state battery when in use.

In one favorable aspect of the manufacturing method disclosed herein, aviscosity of the adhesive when provided to the current collection foilis 100 mPa•s to 5000 mPa•s. Also, if the surface of the currentcollection foil is coated with carbon, the viscosity of the adhesive maybe 500 mPa•s to 1500 mPa•s. In this case, as described above, thecurrent collection foil and the active material layer are adhered moresuitably.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an all-solid-state battery manufacturingapparatus 1; and

FIG. 2 is a flowchart of an all-solid-state battery manufacturingmethod.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, one typical embodiment of the present disclosure will bedescribed in detail with reference to the drawings. Unless specificallymentioned in the present specification, items that are needed forimplementation (e.g., configurations of the all-solid-state battery,etc.) can be understood as items to be designed by a person skilled inthe art based on the conventional techniques of the field. Theall-solid-state battery manufacturing apparatus and manufacturing methoddisclosed herein can be implemented based on the content disclosed inthe present specification and common technical knowledge in the field.It should be noted that in the following drawings, members and portionsthat exhibit the same effects are denoted by the same reference numeralsand described. Also, the dimensional relationships (length, width,thickness, etc.) in the drawings do not reflect the actual dimensionalrelationships.

All-Solid-State Battery

First, an overall configuration of an all-solid-state lithium ionsecondary battery (hereinafter referred to simply as an “all-solid-statebattery” in some cases as well), which is one example of anall-solid-state battery manufactured using the manufacturing apparatusand the manufacturing method illustrated in the present disclosure, willbe described. However, the all-solid-state battery to which themanufacturing method of the present disclosure is to be applied is notlimited to an all-solid-state lithium ion secondary battery. That is,the all-solid-state battery may also be an all-solid-state battery inwhich a metal ion other than a lithium ion is used as a charge carrier,such as a sodium ion secondary battery, a magnesium ion secondarybattery, or the like.

The all-solid-state battery in the present disclosure is manufactured bystacking multiple battery units, which are stacked bodies. The batteryunit includes a positive electrode current collector, a positiveelectrode active material layer, a solid electrolyte layer, a negativeelectrode active material layer, and a negative electrode currentcollector.

The solid electrolyte layer includes at least a solid electrolyte.Examples of solid electrolytes include sulfide-based solid electrolytesand oxide-based solid electrolytes. Examples of sulfide-based solidelectrolytes include glass or glass ceramics that are Li₂S-SiS₂-based,Li₂S-P₂S₃-based, Li₂S-P₂S₅-based, Li₂S-GeS₂-based, Li₂S-B₂S₃-based, orthe like. Examples of oxide-based solid electrolytes include variousoxides having a NASICON structure, a gamet-type structure, or aperovskite-type structure. The solid electrolyte is, for example, in theform of particles. The solid electrolyte layer contains a binder(binding material) such as butadiene rubber.

The positive electrode active material layer includes at least apositive electrode active material. The positive electrode activematerial layer desirably further includes a solid electrolyte, and mayfurther include a conductive material, a binder, or the like. Forexample, known conductive materials such as VGCF and acetylene black canbe used as the conductive material of the positive electrode activematerial layer. For example, a fluorine-containing resin such aspolyvinylidene fluoride or the like can be used as the binder of thepositive electrode active material layer. Various compounds that havebeen conventionally used in this type of battery can be used as thepositive electrode active material. Examples of the positive electrodeactive material include composite oxides with layered structures, suchas LiCoO2 and LiNiO₂, composite oxides with spinel structures, such asLi₂NiMn₃O₈ and LiMn₂O₄, and composite compounds with olivine structures,such as LiFePO₄. The same type of material as the solid electrolytecontained in the solid electrolyte layer can be used as the solidelectrolyte in the positive electrode active material layer. Thepositive electrolyte active material is, for example, in the form ofparticles.

The negative electrode active material layer includes at least anegative electrode active material. The negative electrode activematerial layer desirably further includes a solid electrolyte, and mayfurther include a conductive material, a binder, or the like. Forexample, a known conductive material such as acetylene black can be usedas the conductive material of the negative electrode active materiallayer. For example, a fluorine-containing resin such as polyvinylidenefluoride can be used as the binder of the negative electrode activematerial layer. Various compounds that have been conventionally used inthis type of battery can be used as the negative electrode activematerial. Examples of the negative electrode active material includecarbon-based negative electrode active materials such as graphite,mesocarbon microbeads, and carbon black. Also, examples of the negativeelectrode active material include a negative electrode active materialin which silicon (Si) or tin (Sn) is used as a constituent element. Thesame type of material as the solid electrolyte contained in the solidelectrolyte layer can be used as the solid electrolyte in the negativeelectrode active material layer. The negative electrolyte activematerial is, for example, in the form of particles.

A positive electrode current collector that is used as a positiveelectrode current collector of this type of battery can be used withoutany particular restriction as the positive electrode current collector.Typically, it is desirable that the positive electrode current collectoris made of a metal that has a favorable conductivity. For example, thepositive electrode current collector may also be constituted by a metalmaterial such as aluminum, nickel, chromium, gold, platinum, titanium,zinc, and stainless steel. It should be noted that the positiveelectrode current collector of the present embodiment is a metal foil(current collection foil), and has a surface that is coated with acarbon layer having a thickness of about 3 µm. A negative electrodecurrent collector that is used as a negative electrode current collectorof this type of battery can be used without any particular restrictionas the negative electrode current collector. Typically, it is desirablethat the negative electrode current collector is made of a metal thathas a favorable conductivity. For example, copper (copper foil) or analloy consisting mainly of copper; aluminum, nickel, iron, titanium,zinc, or the like can be used as the negative electrode currentcollector.

Manufacturing Apparatus

An all-solid-state battery manufacturing apparatus 1 in the presentembodiment will be described with reference to FIG. 1 . Themanufacturing apparatus 1 manufactures the battery unit of theall-solid-state battery by adhering a current collection foil 2 to anactive material layer 3 using an adhesive 5. In one example, in themanufacturing apparatus 1 of the present embodiment, the currentcollection foil 2, which is a positive electrode current collector, isstacked on and adhered to the active material layer 3, which is apositive electrode active material layer. However, the manufacturingapparatus 1 may also be used in the case of adhering the currentcollection foil, which is a negative electrode current collector, to anegative electrode active material layer. Also, hereinafter, in order tosimplify the description, the current collection foil 2 is stacked on(adhered to) the active material layer 3 in a state in which the activematerial layer 3 has not yet been stacked on another layer (e.g., atleast one of a solid electrolyte layer, an opposing electrode activematerial layer, and an opposing electrode current collector). However,the manufacturing apparatus 1 may also stack and adhere the currentcollection foil 2 on the surface of the active material layer 3 that hasalready been stacked on another layer.

The manufacturing apparatus 1 of the present embodiment includes atransport apparatus 10, a press roller 20, a supply/cutting apparatus30, an adhesive provision apparatus 50, and a curing light emission unit60.

The transport apparatus 10 transports the active material layer 3 alonga transport direction CD in a state in which the active material layer 3is supported on a support surface 11. The support surface 11 may be, forexample, a conveyor belt or the like. Although the details will bedescribed later, the support surface 11 is used also as a pressingsurface that presses the current collection foil 2 and the activematerial layer 3. Accordingly, it is desirable that the support surface11 is made of a material having an appropriate degree of rigidity. Inthe present embodiment, multiple active material layers 3 formed at auniform size are transported continuously by the transport apparatus 10.Accordingly, the all-solid-state battery manufacturing time is easilyshortened. Also, in the present embodiment, one (bottom surface) of apair of wide surfaces of the active material layer 3 formed into a flatplate shape is supported by the support surface 11. As a result, theother (hereinafter referred to as “outer surface”) of the pair of widesurfaces faces upward. However, as described before, the active materiallayer 3 transported by the transport apparatus 10 may be stacked onanother layer. In this case, the other layer stacked on the activematerial layer 3 comes into contact with the support surface 11 and theactive material layer 3 faces upward.

The press roller 20 is a member with an approximately tubular outershape or an approximately cylindrical outer shape. In other words, theouter circumferential surface of the press roller 20 is a cylindersurface. The press roller 20 attaches the current collection foil 2 thatis supplied from the outside to the foil attachment surface 21, which isa cylindrical surface. The press roller 20 rotates in an arrow directionPD using the central axis of the cylindrical surface (foil attachmentsurface 21) as the rotational axis 25. The rotational axis 25 extends ina horizontal direction, orthogonal to the transport direction of theactive material layer 3 transported by the transport apparatus 10.

The press roller 20 in the present embodiment includes multipleventilation holes 23 that extend from the foil attachment surface 21,which is the cylindrical surface, to the interior. Although manyventilation holes 23 are provided on the foil attachment surface 21,only a portion of the multiple ventilation holes 23 are indicated by thedotted lines in FIG. 1 . The press roller 20 attaches the currentcollection foil 2 to the foil attachment surface 21 by suctioning a gas(air) from the ventilation holes 23 into the interior.

It should be noted that the press roller 20 (or the control unit of themanufacturing apparatus 1) in the present embodiment switches betweenattachment of the current collection foil 2 to the foil attachmentsurface 21 and separation of the current collection foil 2 from the foilattachment surface 21 by switching between suction of the gas from therespective ventilation holes 23 and stopping of suction (or discharge)according to the position. Specifically, the press roller 20 in thepresent embodiment discharges the air to the outside from theventilation hole 23 which has rotated to the lowest position (i.e., theventilation hole 23 at the closest position to the transport apparatus10) among the many ventilation holes 23 provided in the peripheraldirection. Also, the press roller 20 suctions gas into the interior fromthe ventilation holes 23 located in at least region in the foilattachment surface 21 where the current collection foil 2 is to beattached.

However, it is also possible to change the principle for attaching thecurrent collection foil 2 to the foil attachment surface 21. Forexample, the current collection foil 2 may also be attached to the foilattachment surface 21 using static electricity or the like. Also, if theadhesive force between the current collection foil 2 and the foilattachment surface 21 is weaker than the attachment force (to bedescribed in detail later) of the adhesive 5 between the currentcollection foil 2 and the active material layer 3, the press roller 20need not include the configuration of separating the current collectionfoil 2 attached to the foil attachment surface 21.

The supply/cutting apparatus 30 supplies the current collection foil 2from the outside to the press roller 20. Also, the supply/cuttingapparatus 30 in the present embodiment cuts the current collection foil2 having an elongated shape to a predetermined length and supplies thecut current collection foil 2 to the press roller 20. In the presentembodiment, the supply/cutting apparatus 30 is provided above the pressroller 20. The current collection foil 2 that was cut and supplied tothe upper portion of the press roller 20 attaches to the foil attachmentsurface 21.

The supply/cutting apparatus 30 in the present embodiment supplies thecurrent collection foil 2 to the upper portion of the press roller 20 byrotating a pair of rollers in a state in which the current collectionfoil 2 is sandwiched between the pair of rollers. Also, a cutter isprovided on at least one of the pair of rollers. The pair of rollersrotate, and when the length of the current collection foil 2 to besupplied to the press roller 20 side reaches a predetermined length, thecurrent collection foil 2 is cut by the cutter. The supply/cuttingapparatus 30 continuously supplies the current collection foils 2 of thepredetermined length to the press roller 20. The operation of thesupply/cutting apparatus 30 is controlled by the control unit of themanufacturing apparatus 1. It should be noted that it goes withoutsaying that the configuration of the supply/cutting apparatus 30 can bechanged.

The press roller 20 rotates and moves the current collection foil 2 thatwas supplied by the supply/cutting apparatus 30 and attached to the foilattachment surface 21 from the upper portion to the outer surface of theactive material layer 3 transported by the transport apparatus 10 at thelower position. At this time, the adhesive 5 (to be described in detaillater) provided on the current collection foil 2 is sandwiched betweenthe current collection foil 2 and the active material layer 3.Furthermore, the press roller 20 presses the current collection foil 2and the active material layer 3 in the thickness direction (the verticaldirection in FIG. 1 ) between the press roller 20 and the supportsurface 11 of the transport apparatus 10. That is, the manufacturingapparatus 1 can stack and press the current collection foil 2 and theactive material layer 3 while rotating and moving the current collectionfoil 2 using the press roller 20. Accordingly, it is possible to stack(adhere) the current collection foil 2 and the active material layer 3in a shorter amount of time compared to the case of pressing the activematerial layer using a flat plate or the like.

The adhesive provision apparatus 50 is provided on the movement route(in the present embodiment, the movement route from the upper portion towhich the current collection foil 2 is supplied to the lower portion atwhich the current collection foil 2 is stacked on the active materiallayer 3) of the current collection foil 2 that is rotated and moved bythe foil attachment surface 21 of the press roller 20. The adhesiveprovision apparatus 50 provides the adhesive 5 to the current collection2 attached to the press roller 20.

The adhesive provision apparatus 50 in the present embodiment includesan adhesive roller 51. The adhesive roller 51 is a member with anapproximately cylindrical outer shape or an approximately circularcolumnar outer shape. In other words, the outer circumferential surfaceof the adhesive roller 51 is a cylindrical surface. The cylindricalsurface of the adhesive roller 51 is an adhesive contact surface 52 thatcomes into contact with the adhesive 5. The adhesive roller 51 rotatesin the direction of the arrow AD using the central axis of thecylindrical surface (adhesive contact surface 52) as the rotational axis55. The rotational axis 55 of the adhesive roller 51 is parallel to therotational axis 25 of the press roller 20. Also, the rotation directionPD of the press roller 20 is the direction opposite to the rotationdirection AD of the adhesive roller 51. The distance between theadhesive contact surface 52 of the adhesive roller 51 and the foilattachment surface 21 of the press roller 20 is set to a predetermineddistance according to the adjustment amount of the thickness of thelater-described adhesive 5.

The adhesive provision apparatus 50 includes a supply apparatus 57. Thesupply apparatus 57 supplies the adhesive 5 to the adhesive contactsurface 52 of the adhesive roller 51. Various methods (e.g., dripping,coating, spraying, etc.) can be used as the method for supplying theadhesive 5 to the adhesive contact surface 52 using the supply apparatus57. The adhesive 5 supplied from the supply apparatus 57 to the adhesivecontact surface 52 rotates and moves in the arrow AD direction and istransferred onto the current collection foil 2 attached to the foilattachment surface 21 of the press roller 20. The supply location,supply amount, and supply timing for supplying the adhesive from thesupply apparatus 57 to the adhesive contact surface 52 are suitablyadjusted. As a result, a suitable amount of the adhesive 5 istransferred to a suitable position of the current collection foil 2 thatis being rotated and moved by the press roller 20.

With the manufacturing apparatus 1 of the present embodiment, thethickness of the adhesive 5 on the current collection foil 2 is adjusteddue to the adhesive contact surface 52 of the adhesive roller 51 cominginto contact with the adhesive 5 provided on the current collection foil2. Since the rotation direction PD of the press roller 20 is theopposite direction to the rotation direction AD of the adhesive roller51, the thickness of the adhesive 5 on the current collection foil 2 issuitably adjusted without being adversely influenced by friction or thelike. In one example, in the present embodiment, the thickness of theadhesive 5 on the current collection foil 2 is adjusted to 2 µm or lessby the adhesive roller 51. Thereafter, the current collection foil 2 andthe active material layer 3 is pressed in the thickness direction by thepress roller 20 in a state in which the adhesive 5 whose thickness wasadjusted in advance is sandwiched between the current collection foil 2and the active material layer 3. Accordingly, even if the currentcollection foil 2 and the active material layer 3 are pressed by thepress roller 20, according to which the time of applying the pressingpressure is likely to be shortened, the thickness of the adhesive 5 islikely to reach a suitable thickness or less. As a result, thelikelihood that the shape of the battery unit (stacked body) of theall-solid-state battery will be disturbed due to the influence of thethickness of the adhesive 5. Accordingly, with the manufacturingapparatus 1 of the present disclosure, the current collection foil 2 andthe active material layer 3 are suitably attached in a short amount oftime.

Also, the adhesive roller 51 in the present embodiment transfers theadhesive 5 to the current collection foil 2 of the foil attachmentsurface 21 while adjusting the thickness of the transferred adhesive 5.That is, in the present embodiment, the step of providing the adhesive 5to the current collection foil 2 and the step of adjusting the thicknessof the adhesive 5 on the current collection foil 2 are performed at thesame time. Accordingly, the current collection foil 2 and the activematerial layer 3 are adhered more efficiently.

The adhesive 5 is a photocurable adhesive that is cured due to a curinglight being emitted thereto, and is desirably a photocurable adhesivethat is cured due to a curing light such as ultraviolet rays and/orvisible light rays being emitted thereto. In one example, in the presentembodiment, the adhesive 5 including a photocurable acrylic compound isused. When an adhesive 5 that includes a photoradically-curable acryliccompound is used, an adhesive whose cured surface has pressure-sensitiveadhesion at room temperature is desirable. However, another photocurableadhesive (e.g., at least one of a cationic-photocurable adhesive that isepoxy-based or the like, a silicon-based light-and-moisture-curableadhesive, and the like) may also be used. When a photocurable adhesiveis used, there is no need to heat the adhesive 5, unlike the case wherea hot melt is used as the adhesive. Therefore, the manufacturingefficiency further improves and there is no adverse effect on the memberof the all-solid-state battery due to heat. Furthermore, even if thetemperature of the all-solid-state battery rises during use, theadhesive 5 is not melted, and therefore the shape is not likely tochange either. Accordingly, the current collection foil 2 and the activematerial layer 3 are adhered more suitably.

The curing light emission unit 60 emits the curing light to the adhesive5. The adhesive 5 in the present embodiment starts a curing reactionwhen the curing light is emitted thereto from the curing light emissionunit 60, and the adhesive 5 is sufficiently cured after the pressing ofthe current collection foil 2 and the active material layer 3 by thepress roller 20.

Specifically, at least a portion of the adhesive roller 51 in thepresent embodiment is made of a material through which the curing lightpasses. The curing light emission unit 60 emits the curing light throughthe adhesive roller 51 to the adhesive 5 on the current collection foilattached to the press roller 20. Accordingly, the curing light isemitted to the adhesive 5 while the thickness of the adhesive 5 on thecurrent collection foil 2 is adjusted by the adhesive roller 51.Accordingly, the degree of freedom in the arrangement of the apparatusesimproves and the current collection foil 2 and the active material layer3 are adhered more efficiently. Furthermore, if an adhesive 5 includinga photoradically-curable acrylic compound is used and photocured,polymerization is hindered by the oxygen in the air, and it is knownthat this becomes prominent when the thickness is about several µms. Onthe other hand, as in the present embodiment, by using a configurationin which a material through which a curing light passes, or desirably, amaterial through which ultraviolet light and/or visible light passes isused as the material of the rollers 51, and the curing light is emittedto the adhesive 5 at a location with which the roller 51 is in contact,it is possible to favorably cure the adhesive 5 without causinginhibition of polymerization, even if an adhesive 5 that includes aphotoradically-curable acrylic compound is used.

The viscosity of the adhesive 5 when provided to the current collectionfoil 2 is 100 mPa·s to 5000 mPa·s. In this case, the adhesive 5 issuitably provided to the current collection foil 2 and the adhesion ofthe current collection foil 2 and the active material layer 3 is alsoperformed suitably. More specifically, the surface of the currentcollector foil 2 in the present embodiment is coated with a carbonlayer. In this case, if the viscosity of the adhesive 5 is too low,there is a possibility that the adhesive 5 will excessively soak intothe carbon layer and the current collection foil 2 and the activematerial layer 3 will not be sufficiently adhered. Conversely, when theviscosity of the adhesive 5 is too high, there is a possibility that theadhesive 5 will be unlikely to permeate the carbon layer and thethickness of the adhesive 5 will not be sufficiently reduced.Accordingly, in the present embodiment, by setting the viscosity of theadhesive 5 when provided to the current collection foil 2 to 500 mPa·sto 1500 mPa·s, a case is suppressed in which the adhesive forcedecreases due to excessive permeation of the adhesive 5, while thethickness of the adhesive is set to a favorable thickness.

Manufacturing Method

An all-solid-state battery manufacturing method of the presentembodiment will be described with reference to FIG. 2 . Themanufacturing method illustrated in FIG. 2 is performed using theabove-described manufacturing apparatus 1 (see FIG. 1 ). It should benoted that in the actual manufacturing method, multiple currentcollection foils 2 and multiple active material layers 3 aresequentially stacked. However, in order to simplify the description, inthe flowchart shown in FIG. 2 , a step of stacking (adhering) a currentcollection foil 2 and an active material layer 3 of one set is shown.The all-solid-state battery manufacturing method of the presentdisclosure includes a current collection foil attachment step (S1), anadhesive provision step and thickness adjustment step (S2), a curinglight emission step (S3), and a pressing step (S4).

In the current collection foil attachment step (S1), the currentcollection foil 2 is attached to the foil attachment surface 21 of thepress roller 20. As described above, in the present embodiment, acurrent collection foil 2 with an elongated shape is cut to apredetermined length by the supply/cutting apparatus 30 and is attached(supplied) to the foil attachment surface 21.

In the adhesive provision step, the adhesive 5 is provided on thecurrent collection foil 2 attached to the foil attachment surface 21. Asdescribed above, in the present embodiment, the adhesive 5 is providedon the current collection foil 2 by the adhesive provision apparatus 50.

In the thickness adjustment step, the thickness of the adhesive 5 on thecurrent collection foil 2 is adjusted due to the adhesive contactsurface 52 of the adhesive roller 51 coming into contact with theadhesive 5 on the current collection foil 2. As a result, the thicknessof the adhesive 5 between the current collection foil 2 and the activematerial layer 3 after the later-described pressing step (S4) is morelikely to reach a suitable thickness or less. Accordingly, the shape ofthe battery unit of the all-solid-state battery is less likely to bedisturbed.

In the present embodiment, the adhesive provision step and the thicknessadjustment step are performed at the same time (S2). Specifically, theprovision of the adhesive 5 and the adjustment of the thickness of theadhesive are performed at the same time due to the adhesive 5 suppliedto the adhesive contact surface 52 of the adhesive roller 51 beingtransferred onto the current collection foil 2. Accordingly, themanufacturing efficiency further improves.

In the curing light emission step (S3), the curing light is emitted tothe adhesive 5. As a result, the curing reaction of the adhesive 5 issuitably started, and therefore both the current collection foil 2 andthe active material layer 3 are adhered by the adhesive 5 after beingpressed.

In the pressing step (S4), the current collection foil 2 attached to thefoil attachment surface 21 is rotated and moved by the press roller 20to the outer surface of the active material layer 3 transported by thetransport apparatus 10. Furthermore, the current collection foil 2 andthe active material layer 3 are pressed in the thickness directionbetween the press roller 20 and the transport apparatus 10. Accordingly,the current collection foil 2 and the active material layer 3 areadhered suitably in a shorter amount of time compared to the case ofusing a flat plate or the like.

The technique disclosed in the above-described embodiment is merely oneexample. Accordingly, the technique illustrated in the above-describedembodiment can also be changed. For example, a hot melt or the like canalso be used as the adhesive instead of the photocurable adhesive. It isalso possible to employ only a portion of the multiple techniquesillustrated in the above-described embodiment. For example, only one ofthe technique of adjusting the thickness of the adhesive 5 using theadhesive roller 51 and the technique of setting the viscosity of theadhesive 5 to a suitable viscosity and providing the adhesive 5 to thecurrent collection foil 2 may be employed.

1-8. (canceled)
 9. A manufacturing method for manufacturing anall-solid-state battery in which a current collection foil and an activematerial layer are stacked, the manufacturing method comprising: acurrent collection foil attachment step of attaching the currentcollection foil to a foil attachment surface of a press roller thatincludes the foil attachment surface, which is a cylindrical surface,and that is configured to rotate using a central axis of the cylindricalsurface as a rotational axis; an adhesive provision step of providing anadhesive on the current collection foil attached to the foil attachmentsurface; and a pressing step of rotating and moving the currentcollection foil attached to the foil attachment surface to a surface ofthe active material layer being transported by a transport apparatus byrotating the press roller, and pressing the current collection foil andthe active material layer in a thickness direction between the pressroller and the transport apparatus.
 10. The manufacturing methodaccording to claim 9, further comprising a thickness adjustment step ofadjusting a thickness of the adhesive by bringing an adhesive contactsurface of an adhesive roller that has the adhesive contact surface,which is a cylindrical surface, and that is configured to rotate usingan axis parallel to the rotational axis of the press roller as arotational axis into contact with the adhesive on the current collectionfoil attached to the foil attachment surface.
 11. The manufacturingmethod according to claim 10, wherein the adhesive provision step andthe thickness adjustment step are performed at the same time bytransferring the adhesive supplied to the adhesive contact surface ofthe adhesive roller to the current collection foil attached to the foilattachment surface.
 12. The manufacturing method according to claim 9,wherein the adhesive is a photocurable adhesive that is cured due to acuring light being emitted thereto, and the manufacturing method furthercomprises a curing light emission step of emitting the curing light tothe adhesive.
 13. The manufacturing method according to claim 9, whereina viscosity of the adhesive when provided to the current collection foilin the adhesive provision step is 100 mPa·s to 5000 mPa·s.
 14. Themanufacturing method according to claim 9, wherein a surface of thecurrent collection foil to which the adhesive is to be provided iscoated with carbon, and a viscosity of the adhesive when provided to thecurrent collection foil in the adhesive provision step is 500 mPa·s to1500 mPa·s.